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Radiation Shielding Effect due to Cracks in Concrete Silo Dry Storage Systems

  • Donghee Lee (Central Research Institute, Korea Hydro & Nuclear Power Co. Ltd.) ;
  • Sunghwan Chung (Central Research Institute, Korea Hydro & Nuclear Power Co. Ltd.) ;
  • Taehyung Na (Central Research Institute, Korea Hydro & Nuclear Power Co. Ltd.)
  • Received : 2024.07.10
  • Accepted : 2024.09.04
  • Published : 2024.09.30

Abstract

The concrete silo dry storage system, which has been in operation at the Wolsong NPP site since 1992, consists of a concrete structure, a steel liner plate in the inner space, and a fuel basket. The silo system's concrete structure must maintain structural integrity as well as adequate radiation shielding performance against the high radioactivity of spent nuclear fuel stored inside the storage system. The concrete structure is directly exposed to the external climatic environment in the storage facility and can be expected to deteriorate over time owing to the heat of spent nuclear fuel, as well as particularly cracks in the concrete structure. These cracks may reduce the radiation shielding performance of the concrete structure, potentially exceeding the silo system's allowable radiation dose rate limits. For specimens with the same composition and physical properties as silo's concrete structures, cracks were forcibly generated and then irradiated to measure the change in radiation dose rate to examine the effect of cracks in concrete structures on radiation shielding performance, and in the current state, the silo system maintains radiation shielding performance.

Keywords

Acknowledgement

This work was supported by the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea government the Ministry of Trade, Industry and Energy (No. 2021171020001B).

References

  1. Korea Hydro and Nuclear Power Co., Ltd. Safety Analysis Report for the 4th Extension of Spent Nuclear Fuel Dry Storage Facility of Wolsong Nuclear Power Plant Unit 1, KHNP Report (2004). 
  2. Korea Nuclear Safety and Security Commission, Standards for Radiation Protection, Notice No. 2019-10 (2019). 
  3. Korea Nuclear Safety and Security Commission, Detailed Standards for Structures and Equipment of Interim Storage Facilities for Spent Nuclear Fuel, Notice No. 2015-19 (2015). 
  4. U.S. Nuclear Regulatory Commission, Title 10, Code of Federal Regulations Part 72, Licensing Requirements for the Independent Storage of Spent Nuclear Fuel, High-Level Radioactive Waste, and Reactor-Related Greater Than Class C Waste, 10 CFR 72 (2023). 
  5. International Atomic Energy Agency, Storage of Spent Nuclear Fuel, IAEA Safety Standards Series No. SSG-15 Rev.1 (2020). 
  6. International Atomic Energy Agency. Understanding and Managing Ageing of Material in Spent Fuel Storage Facilities, IAEA Technical Report Series No. 443 (2006). 
  7. T. Na, Y. Kim, D. Lee, T. Kim, and S. Chung, "Irradiation Effect on Silo Dry Storage Systems for CANDU Spent Nuclear Fuel", J. Nucl. Fuel Cycle Waste Technol., 22(2), 117-128 (2024). 
  8. D. Lee, S. Chung, Y. Kim, and T. Na, "Review of Aging Management for Concrete Silo Dry Storage Systems", J. Nucl. Fuel Cycle Waste Technol., 21(4), 531-541 (2023). 
  9. Korea Nuclear Safety and Security Commission, Guidance on Technical Application Standards for Evaluating the Continued Operation of Nuclear Reactor Facilities, Notice No. 2024-1 (2024). 
  10. U.S. Electric Power Research Institute. Irradiation Damage of the Concrete Biological Shield: Basis for Evaluation of Concrete Biological Shield Wall for Aging Management, EPRI Technical Report, EPRI 3002011 710 (2018). 
  11. U.S. Electric Power Research Institute, 2020 Update to Irradiation of Concrete Guidance: Basis for Evaluation of Concrete Biological Shield Wall for Aging Management, EPRI 3002018400 (2020). 
  12. U.S. Nuclear Regulatory Commission, Review of Radiation-Induced Concrete Degradation and Potential Implications for Structures Exposed to High Long-Term Radiation Levels in Nuclear Power Plants, NUREG/CR-7280 (2021). 
  13. O. Kontani, Y. Ichikawa, A. Ishizawa, M. Takizawa, and O. Sato, "Irradiation Effects on Concrete Structures", in: Infrastructure Systems for Nuclear Energy, T.C. Thomas Hsu and C.L. Wu, eds., 459-473, John Wiley & Sons, Ltd., New Jersey (2013).